Weird electrical issue causing car to die after 10 seconds!

[Erik Beckett]

Not sure where to begin on this so I will provide some history first. I installed a Atomic EFI this spring and it has been running good so far. I still run the stock GM distributor and coil in my 67 Camaro. The only thing I have wired different is the 12 volt ignition to the coil. They want 12 volts but it runs fine with 6 volts once it's started. I am still running a stock style alternator with the external voltage regulator.

My issue started today after wiring a radiator with dual electric fans. It's a complete PRC setup so I know it's a quality piece. I have both 12 volt battery wires wired to junction block behind battery. I have the 12 volt ignition going to under dash. I have the two grounds from relays going to the wire designated fan 1 and fan 2 in the Atomic efi harness. And the two orange fan wires going to each fan.

the car would not idle for more then 5 seconds and would die. I tripled checked everything and it is all wired correctly. Car will start and idle then die. I noticed the volts on the handheld was reading really high like in the 20's. So I disconnected the wires for the fan and now everything is identical to how it was before the fan install. The car just idles then dies after. 5-10 seconds. My volts seem fine now but she just won't idle or run.



Not sure what to check. Sitting not running I have 12.5-12.7 volts at battery and at alternator. I am thinking coil for some reason. How do I check a coil? fuel pump works as I can hear it an smell the gas.

Very frustrating, as it all worked perfect before radiator install.

Thanks, Erik

[H2Ogbodies]

Are the fans trying to turn on when you start the engine? Besides your dilemma, it appears you have a pretty high amperage requirement to be running the EFI, electric fuel pump, fans, etc. and trying to do all of it with only a 37A rated alternator...? Assuming its a stock rated one anyway. Heck even the HD 55A alternators would have a tuff time keeping up I would think.

[WallaceMFG]

Are the fans trying to turn on when you start the engine? Besides your dilemma, it appears you have a pretty high amperage requirement to be running the EFI, electric fuel pump, fans, etc. and trying to do all of it with only a 37A rated alternator...? Assuming its a stock rated one anyway. Heck even the HD 55A alternators would have a tuff time keeping up I would think.

I agree, it sounds like the fans and efi are sucking all the juice out of the power system. Coil loses power, car dies.

The high volts is probably the voltage regulator trying to compensate for all the current draw. Ohm's law is Volts = Current * Resistance, so rearranging it you'd get Current = Volts/Resistance. To make up for the amps the fans and efi are using, its increasing the volts from the alternator. The stock alternator probably doesn't have enough juice to run all the electronics you have going, might be time for an alternator upgrade.

[H2Ogbodies]

If you are running a stock v-belt arrangement, a bolt on replacement CS style replacement alternator with 12 and 6 clocking is a 1988 Oldsmobile Firenza with a 2.0 FI 4cyl. If you are going to upgrade to an internally regulated alternator, this is a simple install. You'll need a newer CS alt. plug and swap the 5-rib pulley out for your v-belt one.

I modified customers '70 Monte for this upgrade and also installed a 4ga charging system upgrade kit and it completely stabilized the system voltage @ 14.8 and even with all power accessories on, headlights on, amplified stereo system pounding, etc. the voltage remained @ 14.2 at the bulkhead fuseblock!

So no need for exotic alternators if you want to stay on a budget-grab a lifetime warrantied Firenza alt., convert to internal regulation and upgrade your charging capability and you'll solve your voltage issue...if that's the main problem.

[camrat68]

A good link provided in Tony Huntimer's "How to Build and Modify GM Pro-Touring Street Machines" that can help in choosing the alternator that's right for your car canbe found here-->

http://www.powermastermotorsports.co...ternator_.html

I guess I don't understand why you upgraded to EFI but you're still running an external regulator and a points-style distributor? I'm not being critical, it just seems like you skipped a few steps that everybody that I know has taken. Whatever you do, don't remove the white resistor on the firewall that steps the voltage down to the distributor or you'll weld the points together. At least I know I did. Have you looked into the Pertronix HEI conversion for points distributors?

-Jim

[H2Ogbodies]

I would suggest a budget serpentine swap-that way you'll solve several problems at once. And you don't have to spend big money on catalog parts-a GM style serpentine for pre-97 SBC's are extremely versatile and can be found anywhere. I have several serpentine builds right now involving high capacity power steering pumps and OEM style 6" cased 140A CS style alternators.

[Erik Beckett]

My initial issue was my fault, I missed the efi ecu ground wire to reconnect it. It fell behind the radiator support and I just plain missed it. Car started right up after connected. But then I ran into another issue while testing the fan to turn on. The car would die when the fans would kick on. I assumed it was a volt issue, so I doubled checked everything again. This time I noticed the wires on the positive side of the coil were loose for some reason. I through a new one on and everything's is fined now.

I have a newer alternator sitting on my bench that I would love to hook up. It's a newer internal regulated unit. I need to read up on the conversion to a one wire. Also, I have A MSD ready to run to put in too. I did the efi first since I got such a good deal on it.

Right now it runs and works. Only issue is my efi temp reading is 50 degrees lower then the Autogage gauge I have in the car too. They are both in the Edelbrock manifold but not sure why they read so different? Thoughts?

Thanks, Erik

[H2Ogbodies]

You don't want to do the 1-wire alternator swap-do a conversion for an internal regulator but keep the system running as a 3-wire setup. You should upgrade to a remote voltage sensing by running your accessories off a remote junction. I suggest upgrading to a 4 ga charging system and you can keep your horn relay in its factory location since it doubles as a convenient +12v bussbar. Do some searching on GM remote voltage sensing for info on why its superior to running a 1-wire. If you need advice or info on building a 4ga. upgrade kit for use with remote sensing for use with your alternator, send me a PM and I would be more than happy to send you some ideas/diagrams on the most efficient way to re-wire your stock charging system.

[Erik Beckett]

H20gbodies,

I just sent you a PM.

Thanks, Erik